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Biomedical subjects

M Buser

Publications and source records attributed to M Buser.

At least 19 recordsLinked to original sources
PubMed1992

Beta-endorphin and neurotensin in brainstem and cerebrospinal fluid in the sudden infant death syndrome.

Beta-endorphin (BE) and neurotensin (NT) are two neuropeptides which induce apneas. In infants who died of Sudden Infant Death Syndrome (SIDS) we measured, in brainstem and CSF, BE and NT by IRMA and RIA respectively. BE and NT levels are compared to same aged infant and adult controls. CSF BE level was significantly higher in SIDS than in the two control groups (86 +/- 14 vs 33 +/- 13 and 16 +/- 5 pmol/l). In 6 SIDS victims NT and BE were assayed in 5 brainstem sections, each of them divided in median, intermediate and lateral parts. We found high levels of BE in every fragment (3-11 pmol/mg protein) while NT elevated values were restricted to the mesencephalic regions (1.4-12 pmol/mg), the medial pons (6 pmol/mg) and the intermediate parts of the medulla (including the olive: 1.3-1.6 pmol/mg). These results support the hypothesis that NT and/or BE could induce or participate to the fetal issue of SIDS.

Adult↗
PubMed1991

Sex and side differences of cerebral arterial caliber.

The diameter of 261 middle cerebral and 225 anterior cerebral arteries was measured on half axial antero-posterior (ap) view, and the diameter of 217 internal carotid arteries on side view angiograms. Mean diameter was significantly larger by 9.3%, 8.8% and 9.7% respectively in males than in females. In the females the vessels of the left hemisphere were wider but not significantly so than those of the right hemisphere, and the contrary was true for the males. In both sexes the side difference was reversed in the eighth decennium. There was no correlation of vessel diameter with age except for a statistically significant increase by 7.8% of right middle cerebral artery diameter in males from the fifth to the sixth decennium.

Adolescent↗
PubMed1991

[Morphology and function of macrophages in AIDS in broncho-alveolar lavages (BAL)].

HIV infects susceptible T-cell and mononuclear phagocyte targets. Unlike the dramatic changes that occur with T-cells during HIV disease, changes in monocyte and macrophage phenotype and function are qualitatively minimal. The aim of the study was to quantitatively analyze the morphology of macrophages in broncho-alveolar lavages in patients without AIDS, with AIDS, with AIDS complicated by Pneumocystis carinii and in carcinoma patients. In patients with AIDS, the nuclei of macrophages demonstrate a higher integrated optical density (2P less than 0.10), are bigger in size (2P less than 0.05) and have less notches (2P less than 0.02).

Acquired Immunodeficiency Syndrome↗
PubMed1991

Some fundamental aspects of morphometry in clinical pathology, demonstrated on a simple, multipurpose analysis system.

The aim of this study was (1) to investigate the value of morphometry, (2) to fix a set of parameters suitable for analyzing diagnostic problems, and (3) to create a general strategy for data storage and for user-friendly data management. The intrinsic value of morphometry lies in the fact that in contrast to other morphologic methods, it permits the presentation of findings in the form of numbers. The following set of morphometric parameters, in the broad sense of the term morphometry, is standard in our laboratory: planimetric parameters (shape descriptors), parameters of the gray value histogram (descriptors of the general gray value distribution), texture parameters (descriptors of the correlation between various image segments), invariant moments (descriptors of the size and localization of textural image segments) and densitometric parameters. The introduction of morphometric procedures into the daily routine is facilitated if data registration and evaluation are performed separately. Original data generated by direct measurement are primary or raw data, which are stored as such. In a separate, second step these raw data are used to compare more or less complex morphometric parameters, which are called "secondary data". A system designed for separate data registration and evaluation can easily be adapted to new methodologic developments. For instance, primary data on objects (gray values, coordinates of the contour) measured one time in the past can be reused at any other time for computing new features from these data. This procedure is comparable to the possibilities in immunohistochemical staining: new immunohistochemical stains can be applied to newly prepared sections of old tissue blocks.

Computer Communication Networks↗
PubMed1991

The significance of morphometric methods in cytologic diagnostics: differentiation between mesothelial cells, mesothelioma cells and metastatic adenocarcinoma cells in pleural effusions with special emphasis on chromatin texture.

Opinions differ widely as to the value of morphometric techniques for differentiating between mesothelial cells, mesothelioma cells and metastatic adenocarcinoma cells in pleural effusions. The significance of the changes in the chromatin structure to differentiate between these three cell types was stressed by various scientific groups only qualitatively, and until now no group has used digital methods to quantify chromatin structures. The controversy about the value of morphometric methods was the reason for conducting the following study. We wanted to investigate (i) the importance of various planimetric and texture parameters as well as invariant moments as morphometric discriminators; and (ii) to set up a data structure to make possible the further diagnostic use of the multivariate morphometric analyses method for other applications. The present findings show that nuclear size and form are not the decisive factors in differentiating between reactive cells and mesothelioma cells, but pixel related texture parameters and invariant moments are. All parameter types used showed differences between reactive cells and cells of adenocarcinoma metastases. Invariant moments and shape descriptors, but not texture parameters are used to discriminate between mesothelioma cells and cells of adenocarcinoma metastases.

Adenocarcinoma↗
PubMed1990

[Incidence and distribution of tumor disease in relatives. 1. Degrees of stomach carcinoma patients].

The incidence and distribution of malignancies have been analyzed in 435 first degree relatives of 56 patients with histologically proven stomach cancer following the collection of detailed family histories. Eleven stomach cancers were found whereas only three could be expected from age and sex matched incidence data of the local tumour registry. The incidence of all other cancer entities corresponded to that of the whole population. In general, more attention should be paid to the family history, since, among other criteria, it may help to identify individuals at risk and therefore allow the early detection of stomach cancer.

Adult↗
PubMed1990

Malignancies in families of women with medullary, tubular and invasive ductal breast cancer.

Breast cancer seems to represent a heterogeneous group of neoplasia originating from the parenchymal epithelium of the mammary gland. Family studies combined with genetic epidemiological analyses and histological evaluations were used to gain an insight into this nosological entity. Special emphasis was given to the type and frequency of neoplasia in close relatives. This study represents pedigrees of 36 histologically defined pure tubular and 22 pure medullary breast cancer patients as well as 171 with the invasive ductal form. The incidence of cancer in the first degree relatives of all three groups is compared to that of the local population. The first degree relatives did not have a higher risk (RR) for the neoplastic diseases. However, breast cancer occurs more frequently in the female relatives of all three groups. Other cancers have different relative risks.

Adenocarcinoma↗
PubMed1990

Prospective endoscopic study of stress erosions and ulcers in critically ill neurosurgical patients: current incidence and effect of acid-reducing prophylaxis.

We studied prospectively 40 critically ill neurosurgical patients who required prolonged mechanical ventilation to determine the current incidence of stress-related gastroduodenal erosions and ulcers, and to assess endoscopically the efficacy of acid-reducing prophylactic treatment. Nineteen patients were randomized to receive ranitidine plus antacids if necessary to maintain gastric pH at greater than or equal to 4. The remaining 21 patients were given no drug prophylaxis. Gastric pH was significantly (p less than .001) higher in the treated group: 78% of pH readings were at greater than or equal to 4 as compared to 32% in the control group. However, after five study days, incidence and severity of stress lesions were similar in the two groups: nine patients in each group had more than five erosions, one treated patient had a gastric ulcer, and one control patient had duodenal ulcerations. No patient experienced clinically relevant upper GI bleeding. The lack of severe stress bleeding and the low ulcer rate contrast with results from earlier reports on similar patient populations. Furthermore, drug prophylaxis had no detectable benefit, as assessed endoscopically. These findings suggest that routine stress lesion prophylaxis may not be necessary in critically ill patients with comparable risk factors.

Adolescent↗
PubMed1990

[Prerequisites for the application of statical morphometry in diagnostics].

The aims of the present paper were: 1. to test a set of parameters suitable for quantifying morphological features; 2. to create a generally valuable strategy for data storage and for a user friendly data management; 3. to examine the parameter set and the conception for an optimal data management by the quantification of cytological specimens of pleural effusions. The significance of a distinction between "primary parameters" (data directly captured during the measurement) and "secondary data" (data calculated from the primary data) is explained. In the first step of classification of the cytological specimens 81.8% of the patients with reactive alterations of mesothelial cells (n = 11) and 100% of the patients with tumours (mesotheliomas and metastasis of adenocarcinomas) (n = 19) were correctly classified with the aid of a little "expert system". In the second step (discrimination between mesotheliomas (n = 6) and metastasis of adenocarcinomas (n = 13] all patients were correctly classified.

Cytodiagnosis↗
PubMed1989

Testicular and vascular changes in children and adults with varicocele.

We analyzed bilateral testicular biopsies of 188 infertile patients with idiopathic left varicocele. The left side had significant pathological tubular testicular changes compared to the right side, whereas in only 7 per cent of the patients tubular damage was more pronounced on the right side. The Leydig cell pathological score was identical in both testes in 95 per cent of the patients. However, the lower the Leydig cell pathological score the better the testicular histology, suggesting an association between Leydig cell score and testicular function. Of the 188 patients 11 boys and 8 adults were randomly selected, and they displayed clear endothelial proliferative lesions of the capillaries at the ultrastructural level. Proliferative endothelial lesions in the patients with varicocele preceded the testicular changes. This, together with the prevalence of tubular damage at the site of the varicocele and the reversibility of these changes postoperatively, emphasizes the deleterious effects of varicocele as a cause of infertility in these patients. Early surgery for boys in whom the first signs of testicular atrophy occur is highly recommended.

Adolescent↗
PubMed1989

A simple "expert system" for morphometric evaluation of cells in pleural effusions.

Quantitation in diagnostic pathology serves to improve both diagnostic reliability and the prognosis of various malignant tumors. Unfortunately, flexible, user-friendly, reasonably priced and compatible morphometric systems are hardly available on the market. A modular Apple II PC-based system was therefore developed in-house. It records stereologic, planimetric and digital image analysis data and calculates secondary parameters. Detailed statistical analyses can be performed, after data transfer, on larger computers. A typical application of diagnostic morphometry is to determine whether, and with which probability a patient with an unclear histopathologic finding can be assigned to one or more groups of patients with known diseases and prognoses. To this end morphometric data of the patient under investigation are compared with other patient data stored in an expert system. This paper describes the concept of an expert system carried out on the Apple II PC system mentioned above and outlines the evaluation procedures. Invariant moments were used to describe nucleus textures. Results obtained from the cytological analysis of pleural effusions demonstrate that with this approach it is possible to differentiate between normal mesothelium, mesothelioma and metastases of adenocarcinomas.

Adenocarcinoma↗
PubMed1989

Role of gastric colonization in nosocomial infections and endotoxemia: a prospective study in neurosurgical patients on mechanical ventilation.

The role of gastric microbial colonization in nosocomial infections and endotoxemia was investigated prospectively in 40 neurosurgical patients requiring mechanical ventilation for greater than 48 h. Each was studied up to 7 d. Swabs from the nose and oropharynx were cultured at admission, and aspirates from the stomach and trachea were cultured daily until enteral alimentation was started. Patients were evaluated every second day for endotoxemia and coagulation activation. Of 153 gastric aspirates, 66.7% contained microorganisms at a mean quantity of 10(7) cfu/ml. Nosocomial pneumonia occurred in 15 patients, septicemia in 5, and meningitis in 1. The stomach was the evident source of infection in only 1 patient with pneumonia. Of 140 plasma samples, 12 (8.6%) from 10 patients showed detectable endotoxin levels, but there was no association between endotoxemia or coagulation activation and the presence of microorganisms in the stomach. The stomach was not an important source for nosocomial infections or endotoxemia, even in patients with high gastric pH.

Adult↗
PubMed1989

Digital image analysis in cytological diagnosis: a morphometric analysis on pleural mesotheliomas.

In the course of the last years digital image analysis has become increasingly important in the field of quantitative pathology. This may be due to the technical development of computers which have now reached a high user-friendly standard. In the present paper we present: (1) the development of a simple system for the measurement of digital image analysis; (2) the development of a general data structure applicable to various measurements and classification strategies; and (3) the analysis of the value of invariant moments (IM) as regional descriptors to distinguish mesothelial cells from mesothelioma cells in cytologic smears of pleural fluid. The results show that the invariant moments contain information concerning the geometric distribution of the grey values of the pixels as well as the staining intensity. The invariant moments present combination parameters and are therefore ideal morphometric parameters. With the invariant moments 7 out of 7 patients with mesotheliomas and 8 out of 11 control subjects could be assigned correctly in a nonparametric discriminant analysis procedure.

Cell Nucleus↗
PubMed1988

[Community prevention by the "Turning Aarau into a Healthy City Foundation". 10 years' activity 1977-1987. Retrospect and prospect].

In 1987, the foundation "Aarau-healthy city" celebrated the 10th anniversary of its activities in community-oriented prevention (including the National Research Program No. 1 NRP 1). This article presents the prevention activities within the last four years, discusses the results of a random sample survey among the Aarau population and draws conclusions for the future.

Cardiovascular Diseases↗
PubMed1987

Development of cryptorchid testes.

Development of normal germ cells during childhood is a continuous process which ends at puberty. Cryptorchid gonads have severe impairment of their germ cell development which is more pronounced the higher the gonads are situated. However, all newborns with intra-abdominal testes had a normal number of germ cells. This strongly supports the theory that cryptorchidism is a disease and not a malformation. As a consequence, adequate and early treatment of cryptorchid boys should be undertaken in order to preserve good chances of fertility.

Biopsy↗